Re: Simple Permutations and Combinations Problem

That what I would understand by " the 10 CDs Shared between Dai and Evan in odd number of CDs" as two separate and odd selections of CDs that always add up to 10 CDs (complementary), each for Dai and Evan.

I found out these possible5 ways of combining the two selections as follows:

Re: Simple Permutations and Combinations Problem

Originally Posted by zikcau25

That what I would understand by " the 10 CDs Shared between Dai and Evan in odd number of CDs" as two separate and odd selections of CDs that always add up to 10 CDs (complementary), each for Dai and Evan.

There is a more systematic way to do this.
If you have a set of ten there are $2^{10}$ subsets of the set. Half have an even number of elements the other have odd number.
If Dai gets an odd number of elements then there are an odd number of elements are left for Evan.